Free and Premium Cisco 100-490 Dumps Questions Answers

The command that returns the user to the main configuration prompt from the interface configuration prompt is exit. When you are in interface configuration mode on a Cisco device and you want to return to the global configuration mode, you use the exit command. If you want to go all the way back to privileged EXEC mode, you would use the end command or press Ctrl-Z1.

The show cellular unit network command in Cisco IOS is used to view detailed information about the cellular modem and the network it's connected to. Here's the type of information this command usually displays:

Network Status: Whether the device is registered on the cellular network.

Carrier Information: The name of the cellular network provider.

Technology: The cellular technology in use (e.g., 3G, 4G/LTE).

Signal Strength: Signal strength indicators like RSSI and RSCP.

Cell Site Information: Data about the cell tower or base station the device is connected to.

IP Address: The IP address assigned to the cellular interface.

Why other options are less likely:

show cellular unit radio: Provides information about the radio module itself, such as its state and power levels.

show cellular unit hardware: Focuses on hardware-level information of the cellular unit.

show cellular unit profile: Displays configuration details of the cellular profile used to connect to the network.

References:

Cisco command documentation for different show cellular options:

The configuration register on Cisco routers and switches controls specific bootup behaviors. Here's how to modify it:

1. In ROMmon Mode:

rommon>confreg 0x2102 : This command is used when the device is in ROMmon mode (a basic operating system loaded when the full Cisco IOS cannot be found). ROMmon offers limited functionality and is often used for troubleshooting or password recovery.

2. In Global Configuration Mode:

router(config)#config-register 0x2102 : This command is used from within the Cisco IOS itself when you have normal access to the router. You would enter privileged EXEC mode and then global configuration mode to use it.

Importance of Configuration Register Settings:

The most common reasons to modify the configuration register are:

Password Recovery: Setting the configuration register to 0x2142 tells the router to ignore the startup configuration (stored in NVRAM), allowing you to bypass password protection.

Changing Boot Behavior: Settings can control the boot sequence, such as specifying where the Cisco IOS image should be loaded from.

References:

Cisco Configuration Register:

Understanding the Configuration Register (Cisco):

When you initially log in to a Cisco router, the default operating mode is user EXEC mode. This mode provides a limited set of basic monitoring commands but does not allow for any configuration changes to the router’s settings. To make configuration changes, you must enter privileged EXEC mode (often accessed by the enable command), which offers a wider range of commands that allow for the viewing and modification of the configurationGlobal configuration mode is accessed from privileged EXEC mode to modify the router’s configuration, and ROM monitor mode is a low-level mode used mainly for recovery purposes1.

Cisco NX-OS has added support for Python scripting to help manage user networks. Python is a powerful and versatile scripting language that is widely used for automation tasks, including network management. Cisco NX-OS leverages Python to enable network administrators to write custom scripts and programs that can interact with the network operating system, automate repetitive tasks, and integrate with other systems and APIs. This support for Python scripting is part of Cisco’s commitment to network programmability and automation, allowing for more efficient and flexible network operations12.

The type of memory used to store Cisco IOS Software permanently is flash memory. Flash memory is non-volatile, meaning it retains its content even after the device is powered down or restarted. It is commonly used in Cisco devices to store one or more Cisco IOS software images, as well as other files such as backup configuration files. This allows the device to reload the operating system after a reboot without the need to retransfer the IOS image

A. Correct. SSH, or Secure Shell, is indeed a protocol that provides a secure remote access connection to network devices. It encrypts the data to ensure secure transmission over insecure networks like the internet1.

C. Correct. Telnet connections are not secure and are terminated when a router reboots. This is because Telnet does not have any mechanism to maintain the connection in case of network interruptions or device reboots1.

B, D, and E are incorrect because: B. SSH uses TCP port 22 by default, not port 23, which is used by Telnet1. D. Telnet does not provide a secure connection; it transmits data in plain text, which can be intercepted easily1. E. SSH is preferred over Telnet for security reasons because it provides encrypted connections and authentication mechanisms, which Telnet does not1.

References :=1: GeeksforGeeks - Difference between SSH and Telnet 2: phoenixNAP - Telnet vs. SSH: How Is SSH Different From Telnet? 3: Guru99 - Telnet vs SSH – Difference Between Them 4: Difference Between - Difference Between Telnet and SSH

IPv4 addresses consist of four octets, each ranging from 0 to 255. The addresses are used to uniquely identify devices on a network.

A. 255.255.255.255 is reserved for broadcast messages to all hosts on the local network, so it cannot be assigned to a single host.

B. 10.1.1.20 falls within the range of private IP addresses (10.0.0.0 to 10.255.255.255) and can be assigned to a host within a private network.

C. 0.0.0.0 is used to denote an unknown or non-applicable target address, often used as a default route, and cannot be assigned to a host.

D. 192.168.10.15 is also within the range of private IP addresses (192.168.0.0 to 192.168.255.255) and can be assigned to a host within a private network.

E. 292.10.3.4 is not a valid IPv4 address because the first octet exceeds the maximum value of 255.

References :=

IPv4 Addressing

Valid IP Address

IP Address Validation

A DTE (Data Terminal Equipment) device is an end instrument that converts user information into signals or reconverts received signals. In the context of networking, a router can be considered a DTE device because it is typically at the user end of a user-network interface and serves as a data source or destination. It communicates with the data circuit-terminating equipment (DCE), such as a modem, to send and receive data across the network345.

References := Wikipedia, Techopedia, Network Encyclopedia

The data link layer of the OSI model, which is Layer 2, defines how data is formatted for transmission and controls access to the physical media. This layer is responsible for the node-to-node delivery of data and handles error detection and correction from the physical layer. It also manages the way data packets are sent over the network, including the framing, addressing, and flow control. The data link layer ensures that messages are delivered to the proper device on a LAN using hardware addresses (MAC addresses) and translates messages from the network layer into bits for the physical layer to transmit

TFTP, or Trivial File Transfer Protocol, is a simple protocol used for transferring files. Unlike other file transfer protocols, TFTP operates on top of the User Datagram Protocol (UDP), which is a connectionless protocol. This means that TFTP does not establish a persistent connection between the client and server, and it does not guarantee reliable delivery of packets, error checking, or correction. TFTP is typically used in scenarios where simplicity and minimal memory footprint are more critical than the need for reliable delivery, such as when booting a device over a network123. References := Wikipedia, GeeksforGeeks, PyNet Labs

The correct IPv6 address notation follows the format of eight groups of four hexadecimal digits, separated by colons. The address must have exactly eight groups unless it uses the double colon (::) to represent consecutive groups of zero value. The double colon can only appear once in an address to avoid ambiguity.

Option A is incorrect because it includes a subnet mask (/128) which is not part of the actual address notation. Option B is incomplete as it does not contain enough groups and ends with a single colon. Option C has too many groups (nine instead of eight) and is therefore not a valid IPv6 address. Option D is the correct notation with eight groups of four hexadecimal digits, where necessary leading zeros are included.

References :=

IPv6 Address Types, Notation, and Structure Explained1.

IPv6 address formats - IBM2. =========================

Router

The AUX (Auxiliary) port on a router is used for dial-in access for CLI (Command Line Interface) management purposes. It is typically connected to a modem and allows an administrator to dial into the router’s CLI for remote management. This port is not used for passing normal network traffic, which differentiates it from other ports like Fast Ethernet or Gigabit Ethernet that handle regular data flow. The AUX port is specifically designed as a backup async port for management access1.

While the initial answers focused on the most common causes, here's why the other options could also contribute to an interface being stuck in the "up/down" state:

A. Speed or Duplex Mismatch: Devices on either end of an Ethernet connection need to use compatible speed (e.g., 100 Mbps, 1 Gbps) and duplex (full-duplex or half-duplex) settings. Mismatches can prevent the line protocol from coming up even if the physical link is established.

B. Layer 2 Mismatch in Encapsulation Type: Some protocols used on Ethernet networks, like ISL and 802.1Q, have specific encapsulation requirements. If devices on each end aren't using the same encapsulation type, the line protocol will likely remain down.

C. The Ethernet Interface Has Been Manually Disabled: Correct! Administrators can put an interface in a shutdown state using commands like shutdown. This brings down the line protocol even if the physical connection is good.

D. Keepalives Are Not Being Received by the Local Device: While less likely to be the sole cause, issues with keepalive mechanisms used in some routing protocols could potentially lead to the line protocol going down. If the local device expects keepalives and doesn't receive them, it might assume a connectivity problem and affect the interface status.

E. The Ethernet Cable Might Not Be Attached Properly: While a disconnected or faulty cable would usually make the interface down/down, it's possible in some scenarios for a partially connected or damaged cable to result in a link being detected (Layer 1 up) but with errors preventing the line protocol (Layer 2) from initializing.

Troubleshooting network issues often involves considering multiple factors and testing different possibilities. The "up/down" status gives important clues but might have several potential root causes.

Microsoft Notepad is the preferred text editor for working with Cisco configuration files and other simple text documents for several reasons:

Plain Text Focus: Notepad is designed specifically for plain text editing. It does not add any formatting, hidden characters, or metadata that could interfere with the configuration file's structure.

Cisco Syntax Compatibility: Cisco configurations rely on specific syntax and spacing. Notepad preserves these elements accurately.

Universality: Notepad is a basic text editor included in all versions of Windows, ensuring accessibility and eliminating the need for additional software.

Why other options are not ideal:

Microsoft Word: Word is a word processor and includes formatting, fonts, and other features that are not compatible with Cisco configuration files. This formatting can corrupt the configuration.

Microsoft Access: Access is a database management system, not suited for text file editing.

Microsoft Excel: Excel is a spreadsheet application and adds its own structure and formatting that conflicts with configuration file formats.

To assign a static IP address to the Ethernet port on a computer, particularly in a Windows environment, you would navigate to the Network and Sharing Center. From there, you would access the adapter settings, select your local area connection, and then enter the properties for Internet Protocol Version 4 (TCP/IPv4). Within the properties, you would choose the option to use a specific IP address and enter the desired IP information, including the IP address, subnet mask, and default gateway. This process sets a static IP address for the Ethernet port, ensuring that the computer will always use the same IP address every time it connects to the network, which is useful for various network configurations and applications. References := How to Assign a Static IP Address in Windows 10 or Windows 11 - How-To Geek, How to Set Up a Static IP Address | PCMag

DRAM, or Dynamic Random-Access Memory, is the type of memory that is erased when a Cisco device is rebooted. DRAM is used to store the running configuration and routing tables of the device. Since DRAM is volatile memory, its contents are lost when the device is powered down or restarted. This is in contrast to non-volatile memory types like flash and NVRAM, which retain their contents even after a reboot1. References := Types of memory on a Cisco device - Study-CCNA

The Xmodem option that enhances error checking when copying an image to flash memory is the -e option. This option enables error checking to ensure the integrity of the file being transferred. Xmodem is a protocol that uses checksums or cyclic redundancy checks (CRC) to detect errors during the transfer. The -e option specifically invokes CRC error checking, which is more reliable than the basic checksum method, providing an additional layer of verification that the copied image is free from errors. References := The information is based on standard practices for using the Xmodem protocol for file transfers in networking devices, as outlined in Cisco’s documentation and support forums1.

The image provided shows a networking device connected to a laptop via a console cable. Based on the visual indicators and standard port designs:

C. 3 is a USB 5-pin mini USB Type B port: The port labeled “3” on the laptop is smaller than a standard USB Type A port, which suggests it is a mini USB Type B port, commonly used for connecting to networking devices for console access.

E. 2 is a USB 5-pin mini USB Type B to USB Type A console cable: The cable labeled “2” has one end that fits into the mini USB Type B port on the laptop (as identified in point 1), and the other end, which is not clearly visible in the image, is inferred to be a USB Type A connector that would typically connect to a computer’s USB port.

To gain console access to a Cisco switch, two types of ports on a laptop can be used: DB-9 and USB. The DB-9 port is a traditional serial port that is often used with a DB-9 to RJ-45 console cable to connect to the switch’s console port1. However, as modern laptops may not have a DB-9 port, a USB to Serial adapter can be used instead, which creates a virtual COM port that can be used to connect to the switch1. The USB port can also be used directly if the switch has a USB console port, which is common on newer Cisco devices. These ports allow for direct physical connection to the switch for configuration and management purposes. References := Access the CLI via PuTTY using a Console Connection on 300 and 500 Series Managed Switches - Cisco, How to connect Switch with console port - Cisco Learning Network

Two standard fiber-optic connectors are Lucent Connectors (LC) and Subscriber Connectors (SC). The Lucent Connector, commonly referred to as LC, was developed by Lucent Technologies and is characterized by its small form factor with a 1.25mm ferrule. It is widely used in high-density applications due to its compact size and square shape1. The Subscriber Connector, or SC, is known for its push-pull latching mechanism and uses a 2.5mm ferrule. It is a square-shaped, duplex connector that has been a dominant fiber optic connector for decades due to its performance and reliability12.